Plastic coated lumber and logs

ABSTRACT

A building element having a core of compressed fibrous material and a sheathing of plastic molded over the core.

FIELD

[0001] The present invention relates to building product made from scrap wood or other fibrous material and over molded with a recycled low grade plastic.

BACKGROUND

[0002] Currently, the type of structure that is erected in third world countries to house the poor range from mud huts with leaves and grass on the roof to structures made from bamboo or whatever indigenous material is available. Often such structures are dark and easily penetrated by snakes and insects and do not provide ample weatherability. Occasionally material such as stone is available but unless it is close by it usually involves heavy lifting and a mode of transport. In refugee camps, shelter is provided by various tents ranging from military style to plastic sheets fastened over poles. In large slums around cities such as Cairo, Rio, Bogotá, empoverished families live in shelters that are made from anything that can be found in the landfills or dumped by the roadside. Consequently, there is a need for a building element that can be manufactured locally, is inexpensive and can be easily transported and erected.

SUMMARY OF THE INVENTION

[0003] According to the invention there is provided a building element having a core of compressed fibrous material and a sheathing of plastic molded over the core.

[0004] Preferably the core is made of scrap wood and the plastic is recycled plastic.

[0005] Advantageously, the core and sheath may be elongated and round having an elongated concavity along a bottom and a semi-circular recess with an axis perpendicular to an axis of the core and sheath.

[0006] In an alternative aspect of the invention there is provided a method of forming a building element, namely, bundling fibrous material into an elongated rounded cross section, compressing the bundled fibrous material; and molding plastic around the bundled fibrous material to form a plastic sheath.

[0007] The composite lumber or log is both durable and long-lived lasting up to 50 years without maintenance. It has excellent structural characteristics, thermal properties and a pleasing appearance. Provided in the form of a pre-cut kit, it can be assembled within a few days with minimal expertise.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Further features and advantages will be apparent from the following detailed description, given by way of example, of a preferred embodiment taken in conjunction with the accompanying drawings, wherein:

[0009]FIG. 1 is a perspective view of a log consisting of a fibrous material encased in plastic;

[0010]FIG. 2 is a perspective view of three logs being fitted together at a corner of a structure being assembled;

[0011]FIG. 3 is an assembled log structure without a door, window or roof; and

[0012]FIG. 4 is a partial perspective view of an alternative log in which long pieces of waste wood are encased in plastic.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

[0013] Referring to FIG. 1 a log 10 is formed by first bundling scrap wood and lumber material and then over molding it with recycled mixed plastic being mainly high and low density polyethylene. The log 10 is formed with semi-circular recess 18 at ends, which are to intersect at right angles with another log 10. A pinhole 11 is formed vertically so that it passes into the center of the recess and permits the passage of a retaining pin (not shown). The bottom of the log 10 has a slight elongated concavity 16, which conforms to the curvature of an underlying log 10. The wood is bundled by first filling an elongated mold with scrap wood, compressing the mixture into the shape shown, inserting this core bundle into a a second mold which has a larger cross section and then injecting the plastic between the mold and the compressed wood core. Optionally, a wood-bonding agent can be mixed with the wood in order to enhance the strength of the log.

[0014]FIG. 2 shows how several logs are stacked at an intersection of two walls. In this case log 10A is laid down first and then log 10B is fitted at its recess over log 10A. Next log 10C is fitted over log 10B and log 10A. This methodology is continued until both walls are erected. A final structure 20 is shown in FIG. 3 complete with doorway 22, window openings 24 and roof beams 26. A roof is built atop logs 26 which are thicker at one end than the other to allow for water drainage. The roof can be completed using whatever materials are available such as bamboo, grass, or branches. Similarly, the door and windows can be made from bamboo tied with soft reeds or totally from a material similar to that which is used to make baskets. Alternatively, for a higher grade permanent housing, regular doors and windows can be fitted into the openings as they would be in a traditional log cabin or a prefabricated laminated log building.

[0015] Referring to FIG. 4 an alternative high strength log 30 is made by bundling elongated wood scraps 32, compressing them and then over molding with a plastic sheath 34. The elongated wood 32 provides considerable additional bending strength.

[0016] While logs have been formed using this method, it is obvious that there are a wide variety of shapes that can be made such as rectangular lumber and square posts. A coloring pigment can be added to the plastic if desired.

[0017] It is also obvious that while scrap wood has been recited, many other types of fibrous materials could be used such as bamboo, logging debris, branches, reeds, cardboard tubes and the like.

[0018] Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention. 

I claim:
 1. A building element, comprising: (a) a core of compressed fibrous material; (b) a sheathing of plastic molded over said core.
 2. A building element according to claim 1, wherein said core is made of scrap wood.
 3. A building element according to claim 1, wherein said plastic is recycled plastic.
 4. A building element according to claim 1, wherein said core and sheath are elongated and round having an elongated concavity along a bottom and a semi-circular recess with an axis perpendicular to an axis of said core and sheath.
 5. A method of forming a building element, comprising: (a) bundling fibrous material into an elongated rounded cross section (b) compressing said bundled fibrous material; and (c) molding plastic around said bundled fibrous material to form a plastic sheath.
 6. A method according to claim 5, wherein said fibrous material is scrap wood.
 7. A method according to claim 5, wherein said plastic is recycled plastic. 